Lubricating composition



Patented Feb. 22, 1938 2,108,954 r wnmcarmc comrosrrrox Jones L Wasson,Elizabeth, N. J., assignmto Standard Oil Development Company, acorporation of Delaware No Drawing. Application December 20, .1934,

- Serial No. 758,437

80laims.

The present invention relates to an improved addition agent forlubricating oils and to a meth 06. for producing said agent and likewiseto a lubricating oil containing the addition agent being adapted for useat high temperature, for example, as a motor oil by reason of itsresistance to oxidation, sludge formation and other forms ofdeterioration. This application contains subject matter disclosed andclaimed inmy application Serial No. 163,918, filed September 15, 1937.The invention will be fully understood from the following description.

Motor oils and other lubricants which are subjected to elevatedtemperatures show deterioration by oxidation, sludge formation and thelike. Such deterioration may be checked by the" addition of certainmaterials, for example, oxidation inhibitors for reducing the oxidationrate and dispersing agents for preventing or reducing U sludgeformation. Most of these agents useful for one particular purpose areundesirable from another point of view. For example, most of theoxidation inhibitors raise the Sligh value of an oil. In the presentcase a new addition agent has been prepared which has the remarkableability to check all of the various known forms of deterioration andwithout in any way interfering with or diminishing the value of the oilfor lubricating purposes.

The addition agent which forms the principal feature of the presentinvention isproduced from various high boiling aliphatic materials,among which paraffin waxes and heavy parafiln oils may be taken asexamples. Fatty acids and esters thereof may also be employed such asthe glyceryl or glycol esters, monohydric alkyl esters, alcohols and thelike. The above materials are all characterized by long hydrocarbonchains, for example, containing more than carbon atoms.

Such raw materials are first rendered unsaturated either by cracking,dehydrogenation, de-

hydration or the like and thencaused to react with sulfur chloride so asto form a pro not containing both sulfur and chlorin. Thesulfur isbelieved to be in the form of polysulfide and is corrosive when testedwith a bright copper strip in the usual manner, but as will be noted,the subsequent treatment renders the material noncorrosive. The reactionwith sulfur chloride is accomplished in the well known way, preferablyat ordinary temperatures and with cooling since heat is evolved. Thereaction is not permitted to proceed to such a degree as to producesolid materials but is cut short when the product is still liquid andsoluble in mineral oils. Ordinarily,

the reaction may be accomplished in 1 to 4 hours at atemperature notabove about 225 F. and the reaction may be brought to a. stop either bya. careful control of the amount of sulfur chloride added or by theaddition of alcoholic alkali or 5 other such materials which destroy thesulfur chloride. I

The intermediate product obtained in the ways outlined above is thensteamed, preferably in the presence of alkali so as to remove at least apart 10 of the chlorin and to replace this with hydroxyl groups. Thistreatment also converts the "corrosive" sulfur to a "non-corrosivevariety so that the final com pound will not tarnish copper. The chlorinmay be entirely removed but if it is it reduced to-a small quantity, sayless than .5%, results are quite satisfactory. It will be understoodthat more chlorin than this may be allowed to remain but it is notparticularly advantageous, in fact, it is believed to be preferable 2 toremove the chlorin to as complete a degree as possible. The presence ofhydroxyl groups is indicated by the acetyl value.

The final product may be purified in any desired manner and in the endconsists of an aliphatic hydroxy sulfide or polysulflde soluble inmineral lubricating oils and fluid at ordinary temperatures.

The oils to which the above substance may be advantageously added arehigh boiling petroleum fractions, particularly the lubricating oilsproduced by ordinary refining methods such as distillation, acid,alkali, and/or clay treatment or .the more highly refined oils such asproduced by hydrogenation, destructive hydrogenation, heavy acidtreatment or solvent extraction. It has been observed that the morehighly refined oils show a greater tendency toward rapid oxidation andthis is efiectively checked by the addition of relatively small amountsof the agents prepared in 0 the manner described above. The amountmayvary considerably with the particular oils but it is usually foundthat 1% more; or less gives satisfactory results.

The addition agents may be added also to high 5 boiling'fuels andinsulating oils which are subjected to high temperatures.

As an example of the production of the addition agent and its effects,the following may be considered:

Parafiin wax is cracked by heat at 810 F. liquid phase and under 50#pressure to give a total ,cracked product boiling from about 200 to 650F.

and about 50 to olefin content.

To parts by weight of the cracked wax is u i added parts by'weight ofsulfur dichloride and the temperature is held down below 200 F.duringthe reaction periodof about 1 hour. The product recovered isfluid, soluble in mineral oils and contains about 2% by weight of eachof the elements chlorin and sulfur.

The intermediate obtained above is then refluxed or steamed 'overalcoholic soda for one-half hour, dried and finally recovered. It hasthe following analysis:

. Per cent Carbon 82.67 Hydrogen 14.12 Sulfur 2.07 Chlorin 0.35

Tenn--. 99.21

Acetyl value -1 51.2

undlssolved oxygen which is measured at 15 min-' ute intervals. Theresults are as follows:

Oxidation rate 200 0. Sample cc. 0| absorbed/10 cc.

per 15 minutes 8. A. E. 132-116-82-49 Same 1% hydroxy sulfide17-20-15-15 The Sligh values of the above samples determined accordingto the method given in A. S. T. M. Report D-2, p. 22 (1927) except thatthe time of heating is 24 hours instead of the usual 2 hours were 6.7for the blank and 2.2 for the same containing the addition agent.

Another sample of the addition agent was prepared in the same generalmanner indicated above and when added to a highly refined lubricatingoil of high oxidation rate in proportion of .1% showed an oxidation rateof 37-38-28-152.

The Sligl'r value was 1.2, less than 20% of that of the unblended oil.

In the above description, the agent is described as an aliphatichydroxysulflde or polysulflde and by this it is meant that the hydroxyland sulfur groups are attached directly to the aliphatic chain. It isdefinitely intended to include under this't'erm materials includingcyclic aromatic or naphthenie rings, which may or may not besubstituted, providing that the sulfur and hydroxyl groups are attacheddirectly to the aliphatic chain as indicated. The oils may be blendedwith other known materials to-increase oiliness, thickeners, metallicsoaps, dyes, pour point inhibitors or the like, as in the case of anyother mineral oil.

The present invention is not to be limited by any theory of the methodby which the agents are 'produced or any theory of their activity forthe purposes disclosed, but only by the following claims in which it isdesired to claim all novelty inherent in the invention.

I claim: I

1. An improved lubricating composition of low oxidation rate andtendency to sludge, comprising a lubricating oil having a tendency toform sludge on oxidation and containing as an addition agent a smallamount of an aliphatic hydroxy-sulfide in which the hydroxy radical andthe sulfur are attached directly to the aliphatic group.

2. Composition according to claim. 1 in which the addition agentcomprises an aliphatic hydroxy polysulflde containing a long carbonchain.

3. Composition according tov claim 1 in which the addition agent is apolysulflde containing a carbon chain of at least 10 carbon atoms.

4. Composition according to claim 1 in which the addition agentcomprises a polysuflde derived from a heavy hydrocarbon.

5. Composition according to claim 1 in which the addition agentcomprises a polysulflde derived from paraflin wax.

6. Composition according to claim 1 in which the addition agentcomprises a polysulflde derived from an unsaturated derivative ofparafiin wax by treatment with sulfur mono or dichloride followed bysubstitution of hydroxyl groups for substantially all of the chlorin.

JONES I. WASSON.

